How often should cervical screening be repeated for women with a history of CIN?

For women with a history of cervical intraepithelial neoplasia (CIN), the frequency of cervical screening depends on the grade of CIN and completeness of excision.

• If the woman had low-grade disease (CIN 1) with incompletely excised or uncertain excision, cytology should be performed at 6, 12, and 24 months.
• If the woman had high-grade disease (CIN 2 or CIN 3) with incompletely excised or uncertain excision, cytology should be done at 6 and 12 months, followed by annual cytology for 9 years. Follow-up continues until age 65 or until 10 years after surgery, whichever is later.
• After treatment for CIN, a test of cure (repeat cervical sample) should be done 6 months post-treatment.
• If the test of cure is negative for high-risk human papillomavirus (hrHPV), the woman should be recalled for repeat cytology in 3 years, regardless of age.
• If the 3-year cytology test is negative, she can return to routine recall screening.
• If hrHPV is positive at any point, referral for colposcopy is required.

These recommendations are based on Public Health England guidelines and the NHS Cervical Screening Programme protocols.